Train-control system



Jilly 8, 1930. T. E. CLARKE-T AL 1,770,371

TRAIN CONTROL SYSTEM Filed March 15, 1926 2 Sheets-Sheet 1 INVENTORS A TORNEY July 8, 1930. CLARK ET AL 1,770,371

TRAIN CONTROL' SYSTEM Filed March 15, 1926 2 Sheets-Sheet, 2

INVENTOR H I \1 Y ATTORNEY l uallv operable means for'establishing' a cir Patented July 8, 1930 Trroiaas'n. CLARK AND JAMES dLAnKQoF DETiaoIT, MICHIGAN, assrelvoas To 001% TINUOUS TRAIN, conTRoLcoRron Tron, or DETROIT, MICHIGAN,ACORPORATION OF MICHIGAN V i aazinconraori si'sTEivi I l' a piicat onmaMarsala, 1926; Serial in. 94,754.

This invention relates to the control of railway trains by means of, one orjanother high frequency current propagated in the rails of tracks which are" divided into blocks, a current propagatlng device belng connected to therails of each" block; preferablyfto the exit end thereof, and each pr'op'agatlng device comprising means influenced by; the

current in the block in adv'ance of that to I which such device propagates current, the purpose of controlling such propagation to accord with the traific conditions in a selected number of blocks in advance, and 1ts object is to provide a wayside circuit eXtending along-the trackway of the block from such propagating device, and a series of transformers connected-to said conductors and to the rails so that thepropagated current may be impressed upon'the railsot the block with sufficient uniformity throughout the length of the block. i

A further object ofthis invention isto'pro- .vid'e resonant circuits on a locomotive or other 1 power vehicle, embodying vacuum tubes and collector coils connected thereto and adapted to pick up electro magnetic force from the'charged rails which shalllso affect the tubes that'the plate currents therefrom shall overn theloperation of a .polar neutral relay; to provideian electro-pneumatic valve to control the'operation of air brakes and circuits between a current'source an d the valve'controlled bysaid polar neutral relay; to providefa governor in said circuit sothat when the speed of the' 'vehicle "exceeds the speet which is predetermined forthe con dition under which i the particular current present in the rails is propagated, the'efi ective circuit betweenthe current source and the valve will be opened and'to provide inancuit between the current sourceand the valve which shall remain closed while the vehicle bination of the instrumentalities shown diagrammatically in the accompanying drawings and a particularly pointed out -invthe claims.

in the drawingsFigsiland Q'arediagrams the train control system embodyingfthe present invention; Fig. 2Iis'a perspective'oit a tra nsforineri r Fig.4 is .af dia-gram ating aswitchffroma semaphore. I v r 'Si'milar reference charactersfrefer to like parts throughout the "several views. The rails land 2 are shown divided into blocks A, 13,;and C 'by'ineans of insulations 3 in the usualmanner and'a track installation is connectedto the exit'ends of blocks A and P. The track and locomotive installationseinbody'relays whose'armatures are in.

dicated small'jletters which will be used c l with the designatingcharacters ofithe rela'y s.

Alternatin'gcurrent is supplied to. thetWo line wires5 and 6 from any current source such as a generator G, and each track intall'ai tion embodies a wire 7,"over whiclh current. normallyjflows through primary winding 8 of the main transformer, wire 9,arinature a of a high' resistance, polar-neutral relay l0, wirex12, armature aiof relay 13 and wire 14. Each relay 10 is controlled b ythe current in thevtrack rails of the block ahead and has three conditions, positively or negatively'em:

ergized and de-energized. VVhengit is either positively or negatively energize'd it attracts its ar'inatures a'and b and thus. closesthe circuit to the primary winding'S, but when it is d e-lenergized, V which occurs when; itsblock o track s occupled the circu t to the primary p tive- I j The vacuuin'tubes 1 5' and 16 are the generators of the control currents andtheir filaments receive current from the portion 17- of the secondary'winding of the main transformer, thec'urrent passing over wires 18 and I9, variable resiStance QO and wire 21 to the of mechanism for operninding is opened and the adjacent trackin ttallation forthe next bl ckm, the'rear 1's in- Ice filament of tube :15 and back over wires 23 t and 24 tolwinding- 17. 'Currentfalso passes over wire 18yadj11sta'ble resistance 25 and wire 26 to the filamentof tube 16" and back over wire 24. l p 7 4 p a The'secondary'winding of the main trans former for. the plate'c urrent oftube' 15 com sists iof the parts 17 and 27, while that for the tube 16 consists of the parts 17, 27 and 28. The plate circuit of the tube 15 during the positive portion of the cycle of the current in wires 5 and 6, is over wire 23, coils 17 and 27, wire 32, coil 31 andwire to the plate, while the circuit during the negative portion is over the wire 30, coil 31, wire 32, condenser 38, wires 18 and 19, resistance 20 and wire 21. This circuit carries a pulsating current of high-frequency and causes a pulsating charge in the grid circuit of this tube 15, said circuit consisting of the wires 23, 24 and 41, inductance coil 42, wire 43, extending therefrom to the grid leak 44 and condenser 45, and wire 46.

The coil 42 being the secondary of a transformer of which the coil'31 is the primary, a pulsating charge is impressed upon the grid circuit and negative potential is charged on and discharged from the grid of tube 15, the condenser 45 and grid leak 44preventing positive potential in the grid. This charge and dischargeis probably both the cause and effect of the pulsations in the plate circuitand coil The rate of vibrations and the wave lengths of the currents are controlled by the adjustable condenser 47 which shunts the coil 31.

The plate current of tube 16 flows in one direction from coils 27 a'nd28, over wire 36, inductance coil 35 and wire 34, and in the opposite direction from the plate over wire 34, coil 35, wire 36, condenser 39, wire 18 and adjustable resistance 25 to the filament of tube 16, the condenser 39 serving as a low resistance path for radio-frequency oscillations to by-pass the windings 27 and 28. The plate current, therefore, never flows in the opposite direct-ion through the coils 27 and 28 of the main transformer. The adjustable condenser 37 tunes the plate circuit of tube 16 in resonancewith the plate circuit of the other tube.

The grid of tube 16 is controlled by the inductance coil 31 of tube 15 acting on the inductance coil 48 which connects to the wire 24 by the wire 49 and to the grid leak 50 and condenser 51 bythe wire 52. The wire 53 connects the grid of tube 16 to. its leak and condenser. As the charge in this grid pulsates in unison with the charge in the grid of and with the current in the plate circuit of tube 15, the plate current of tube 16 also pulsates in such unison.

The reason for using two tubes is as fol-.

lows. The track circuit comprising the rails between thewires 66 and 68 and the nearest wires 71 and .7 2 is lengthened and shortened by the trains passing over this portion of the block to which the installation is connected. This change in length of circuit would normally change the wave length of the current flowing in the plate circuit through the reaction between the inductance coils 60 and 59 and coils 57 and 35 which are inductively connected. But the frequency of the pulsations of the current in this plate circuit is controlled by the current in the grid circuit which includes the coil 48 which current always pulsates in unison with the current in the plate circuit of tube 15 which is unaffected by any change in the track circuit. T he rate of vibrations and Wave lengths are therefore controlled by the tube 15 and its circuits. This tube may be of very much less capacity than the tube 16.

In the operations of train control systems employing the track installations above described, great difficulties were met with because the current in the rails dissipated from the input end of the block, which is usually the exit end, toward the entrance end and the mechanism which embodies the present invention has been devised to overcome these difficulties and to insure a substantially constant current of sufficient strength throughout the block. Much of the success of the present invention arose from the proper installation of the transformer shown in Fig. 2, which is admirably adapted for currents of radio frequency.

The transformer (Fig. 2) is in the form of a rectangle and is built up of thin sheets of steel 58 coated with an insulating varnish,

preferably by dipping. A winding is on each core, the primary winding 59 being of finer wire and the secondary winding 60 of heavier wire and of fewer turns so that the output thereof will be of lower voltage but of higher amperage.

The fixed output inductance 57 co-acts with theinductance coil 35 of the plate circuit of the tube 16, and this output inductance is a portion of an oscillating circuit which is from the coil 57 over condenser 62, wires and 63 to primary winding 59. Only a part of the current passes over the wire 63, and the remaining portion of the current passes over the wire 55 to the other transformers positioned along the trackway. From the first primary 59 the current passes over wires 64 and 56 to the output coil 57.

The secondary winding of the first transformer connects to the rails by means of wires 66and 67 and wires 68 and 69respectively, a condenser 70 being inserted to prevent passage of battery currents. The primary windings 59 of the other transformers, which may be of any desired number, connect to the wires 55 and 56 and the secondary windings connect to the'rails 1 and 2 by means of wires 7f and 72 respectively, condensers 70 being again inserted in one of these wires.

The transformers may be adjusted so that the current at all points along the rails will be substantially uniform by so connecting the wires 71 and 72 to the secondary windings 60 of the transformers that proper current output of these windings will be secured by selecting the proper lengths of such windings.

Asthegtransformer next acent, the axle'T, in'any block is most active, the current in the rails at the entrance-end of-a block .whenlthe axle is, at that endlwill beet sufficient strength to properly. ;influence the instrumentalitieson thelocomotive;

Iii-the drawings we assume thatthetraek in advance of block G is unoccupied for two or moreblocks, and the high resistancepolar grammatically and embody thesignal arms- 65 which assumethe solid lineposition, as shown in Fig; "1 when positive current isreceived by the relay 10,{assu me the dotted line position of Fig.1 when negative current is received byv relay 10,-,a'nd'assume the position shown in F 3 when nocurrent is re ceived by. relay 10. These signal arms .are operated by current fromthe station battery 76, and when the armature 10 isswungcglock. wise, by reason ofpositive current received by relay 10, current flows over wire 77, armature 10, wire 78 to the signal post and over; wire 79 back to the battery. ,Thiscauses the signal .arm 65 to assume the intermediate or. dotted line (Fig. 1) or caution position. Current also flows from w1re7 8 over, armature 10 and wire 80 to the signal post causmgthe signal arm to move one step farther to the solid line sosition Fi 1 or clear osition.

If negative current is received by. relay 10, its armatures and cl swing counter-clockwise and current flows only over wire 78 to the signal post and arm- 65 assumes its intermediate position. If no currentfiows from battery 7 6,.as in Fig. 3, the signal arm assumes .the danger position. I

Positive current in relay 10. also causes its armature cto swing clockwise, closing thec'ir: cuit to. relay1811overwire 77, armature '10", wire 78 and armature this relay being connected to the return wire 7 9.- Energized relay 81 attracts itsarmatures a and b and closes the, circuit-consisting of the Wire 82,

armature81 wire ,82 ,-.condenser-83 and wire 84: between the [wires and 32,.thus shunting the condenser 83 into'the circuit of the plate coil 31 of tube 15,-and closes the circuit consisting of wire 85, condenser 86 and wire 87 betweenthe wires 34 and36 of the circuit ofthe plate coill of tube 16, resulting. in an increase of wavelength of the currentpropagated inthe rails by the output coil 57. Thus; the, wave length of the rails throughout the lengths of the blocks,

current forcl-ear' conditions may, be 30,000

meters while that for .caution conditions may bev 25,000iginetersi When the relay 10 receives negative'current, the relays 10 and .lO iare swung counter-clockwise and-the relay 81 is de-energizcd and the caution current is ipropagated bytube 161i When the blockinadvanc'e 'isioceupied, as in block Bfrelay, 10 of station A receives no current and its armatures a and 7) fall, open- .ing the circuit of themaintransformer so that is propagated inthe rails 0t no current block A. v 1 v llach track battery 89 connects to a twoway switch having arms.90 and 91,'one under clear conditions connecting tothe wire 67 andto rail-2 and the other connecting to rail 1 by wire. 92,- relay =13andwirey69 The switch arms -'are connectedto' the adjacent semaphore arm, so that when the signal arm is in solid line position (Fig. 1) the switch isin solid line position so that positive cur rent flows to rail 1. VVhile'any desiredmeans may beemployed to connect the-switch arms 90 and 91 to the semaphore 65', that shown in Fig. 4 may be found useful. A small arm 170 is attached to the shaft of the semaphore and swingswith it. A cable 171 connected toJthe end of this arm attaches'to the bar172 ofinsulating material connecting thearms a.

90 and 91. A spring 17 3 may be .used to pull down the. arms 90 and 91. The range of movement of the arm 170 is from 22% degrees onone side of the perpendicular to 67 degrees on the other, the switcharms being wide enough to keep contact while the arm 170. crosses the perpendicular.

switch arms remain in this position and positive current still flows to rail 1. The switch arms swing counter-clockwise when the signal arm moves to danger position. With block B occupiechrelaylO adjacent the track installation A in the rear receivesno current, battery B being short circuited by axle T and the signal arm at said next station in the rear assumesthe danger position. The

When the signal arm swings 'to'ca ution position the relays 1S are'never energized unlessan axle Tcloses their circuits. I

The traincontrol installation ofv a block,

therefore, isinoperativeunless theblock is occupied, atwhich time therelay 10 at the entrance end of the block is de-energized.

These track installations propagate substan tially uniform electro-magnetic waves in the the wave lengths or absence of current'being automat cally determined by the; occupancy ofthe. track aheach'andsuch propagation taking place only in occupied blocks, thus sav-.

ing current and insuring maximum life of the tubes.

normally supplies current for-the locomotive The locomotive installation shown in the drawings makes use of the generator 99 which headlight, and this genera-tor supplies current to the rotarygenerator or dynamotor D over wires 100, 101 and 102, the return being over the wires 103, 104 and 105. This generator current is preferably of about 32 volts.

The locomotive installation embodies two vacuum tubes 106and 107, the current for the filaments of these being supplied by the generator 99 over wires 100 and 101, resistance 108 and'wire:109 to the filament of tube 107, wires 111 and 112 to the filament of tube 106 and return wires 113 and 105 back to the filament of tube 107 by the wire 109 and to the grid of this tube by the wire 120. grid lead: 121 and condenser 122, an adgustable condenser 123 between the wires 109 and 120 being adapted to tune this circuit to the wave length of the other current propagated in the rails, preferably tot-he caution current. The plate currents for each of these tubes is produced by the dynamotor D and is preferably of about 200 volts. When either of the-collector coils picks up current, a negative potential charge accumulates on the grid ele ment to which the coil is connected. This obstructs the normal action of the tube and few electrons pass to the plate from the filament; hen neither coil receives current, high voltage current flows from the dynamotor D over wire 125, relay 126, wire 127, windings 12 -8 and 129 of a polar neutral relay, and wires 130 and 131 to the plates of the two tubes, the return being over the filament of tube 106, wire 112, filament of tube 107 and wires 109, 101, 102 and 132'. This causes relay 126 to attract its armature ato close the circuit to the red lamp R in the cab, the circuit being over wire100, resistance 134, lamp 55wire 135, armature 126 and wires 104 and The windings 128 and 129 neutralize each other when both receive current, but both are necessary to carry sufi'icient current to energize the relay 126 s'ufiiciently for it to pick up its armature. If either of the windings 128-129 receives current, the relay will pick up the armatures a and b. It coil 114 picks up current, relay 128Vreceives no current and the polar armatures and (Z will swing clockwise, but when coil 115 picks up current, these armatures will swing counter-clockwise.

We have indicated a speed governor 138 having arms 139 and 140 which' normally close the circuits bet-ween common wire 141 and the wires 142 and 143 respectively. This governor is attached to an axle of the locomotive and when the speed of the locomotive exceeds that permitted for danger conditions, say ten miles per hour, the arm 139 swings out and opens the circuit between the wires 141 and 142. When the speed exceeds that for caution conditions, the arm 140 opens the circuit between the wires 141 and 143.

In the presentsystem'we employ an electro-pneumatic train control valve 145 which embodies a normally energized solenoid, which valve connects to the air brake system by a pipe 146, and, when open, permits the pressure in this system to escape by a vent 147, which escape occurs when the solenoid 145 is de-energized.

Referring now to Fig. 1, the positions of the parts indicate reception of current by collector coil 114. Winding 128 receives no current so that winding 129 holds up armatures a and b and swings armatures o and (Z clockwise. Current from the generator 99 flows over wire 100, resistance 134, wire 150, green lamp G., wire 151, armature 129, wire 152, armature 129 and wire 105 back to the generator. This green lamp indicates clear conditions.

Current also flows over wire 100, forestalling key 153, wire 154, electro-pneumatic valve 145, wire 155, armature 129 wires 156 and 152, armature 129 and wire 105 to the generator. 9 The valve 145 will therefore remain closed so long as clear current is picked up by coil 114. I WVhen caution current is picked up by collector coil 115, winding 128 becomes energized and its armatures c and (Z swing counter-clockwise, as indicated by dotted lines in Fig. 1. Currentnow flows from the generator to yellow lamp Y and thence over wire 157, armature 128, wire 152, armature 128 and wire 105 back to the generator.

If the locomotive is running at less than caution speed, current flows from generator '99 to the valve 145 via forestalling switch 153 and over wires 155 and 141, governor arm 140, wire 143, armature 128, wires 156 and 152, armature 128 and wire 105 to the generator. But if the speed is greater than that predetermined for caution conditions, the arm 140 swings out to open this circuit and the de-energized valve 145 opens and the brakes will then reduce the speed to that thus determined.

WVhen no current is picked up by the collector coils, both windings 128 and 129 become equally energized and neutralize each other, their armatures a and b dropping and opening the circuit to the valve 145 which would normally cause the application of the brakes. But this application is not instantaneous because of theflarge volume of air in the train pipe and the small size of the vent 147. If, therefore, the engineer de- 'presses his forestalling key 153 as soonas current passes to thered lamp R, he estab-v lishes acircuit over wires 101, 160, relay 161, wire 162, switch 163,-key153 and wires 164 and 105. Armatures a and blof relay 161" being-picked up, a holding circuit for this relay is closed over wires 100, 101, 160, relay 161, wire 162, armature 161 and wires 165' and 105. The key is now released'and returns to normal position. 7 v

A circuit for valve 115 is also established consisting of wire 100, key 153 and wire 15 1 to the valve and Wires 155, and 141, governor arm 139, wire 112, armature 161 and wires 165 and 105 to generator99r This circuit. is

openedimmediate'ly the locomotive exceeds its danger speed, but this circuit permits the locomotive to move forward to the place where an obstruction has caused the danger conditions of the track station next ahead.

Relay 161 remains energized until the our- 7 rent which energizes it is given a path of lower resistance by the armature 128 when attracted, whlch armature connects the wires 160 and 105 when either of the windings .128

and 129 is energized because of current picked up from the rails by e ther of the receptor coils. A resistance 166 in the wire 160 prevents the generator 99being short I circuited by the last named circuit.

The switch 163 remainsin normalposition until the blast of air from the vent 117 reaches apredetermined volume, which occurs when the valve 115 has been open .a pre determined length of time, say five seconds, a

so that, should the engineer fail to depress his forestalling key within that time, the brakes will bevapplied. The construction and operation of the valve 145 and of the switch 163 are fully set forth in our previous Patent No. 1,697,919 dated Jan. 8th, 1929.

pend upon the occupancy of the track ahead,

the combination of a pluralityof receiving circuits, each tuned to resonance with one of the currents in the rails, an electro-pn'euf matic valve to control the brake system on the vehicle, a current source and a plurality of circuits between it and said valve, whereby current from said source may be conducted to sa1d valve to hold 1t closed, electro-magnetic means for openlng and closing said circuits, a plurality of conductors between said 7 current'source. and said electro-magneticmeans, said electro-magnetic means opening said plurality of circuits to said valve when current is received over both said conductors and opening one or the other of said circuits to saidvalve when receiving current over but one of said conductors, and electron tubes in said conductors and controlled by the currents insaid tuned receiving circuitsto con trol' the flow of current insaid conductors to said electromagnetic means, i I

2. I In an automatic brake system for railway vehicles on track rails carrying'radio-' frequency currents whose wave lengths and presence depend upon the occupancy of the track ahead, the combination'of a plurality of receiving circuits, each tuned to resonance "with one of the currents inthe rails, an

e.lectropneu1nati c valve tocontrol the brake system'of'the vehicle, a current source and a plurality of c1rcu1ts between 11121116. sa1d valve whereby current from said source may be conducted to sa1d valve to hold it closed, electro-magnetm means for opening and closing said circuits, a plurality of condu'c tors between the current source and said electromagnetic means, said electro-mag netio means opening said circuits when current is received over both of said receiving circuits or when no current is receive'dand opening one of said circuits to said valve. when current is received over but one of said receiving circuits, and electron tubes in said conductors and controlled by current in said receiving circuits to control the flow of current in said conductors to said electro magnetic means" '3. In a construction nected'into'the circuits between the electromagnetic means and the valveto open and close said circuits according to the speed of the vehicle. I

1. In a construction as set forth in claim 1,

the combination 'of a normally open additional circuit between the current source and the valve, and a manually operable key a'daptedto close said last namedcircuit so as to permit the Vehicle to proceed when no current 1s received over the receiving cirfcuits.

7 r as described in claim I 2, the combination of a speed governor con- 7 THOMAS E. CLARK. f

JAMES E CLARK. 

